1. Field of the Invention
The present invention, in general, is directed to a power generation and distribution system and, more specifically, to a power generation and distribution system for providing power to one or more motors configured to drive a wheel of a vehicle, such as a locomotive.
2. Description of Related Art
Traction motors are typically used to provide tractive power to move a locomotive. The traction motors are commonly powered using an AC generator. Current multiple traction motor systems use an inverter/chopper to convert the AC output of the electrical generators to DC and then back to AC. However, this process suffers from various deficiencies. First, there is a large amount of electrical energy lost as heat by converting the AC output of the generators to DC and then back to AC using the inverter/chopper. In addition, such prior art systems suffer from slow response times waiting for the control loops to: 1) light off another engine during high peak current demands; and 2) change the voltages/current in response to a changing load.
The use of the inverter/chopper for power conversions also suffers from various deficiencies. First, the inverter/chopper is large, heavy, and expensive. In addition, the inverter/chopper has extremely high EMI emissions which lead to higher engine emissions. Finally, the inverter/chopper cannot feed motor braking energy to other electrical loads and lacks stall and commutator protection.
Furthermore, the auxiliary equipment of the locomotive, such as lighting systems, heating systems, and air conditioning systems, required for use with prior art multiple traction motor system is expensive and must be special ordered. The reason is that such auxiliary equipment requires a variable voltage/frequency that must be supplied by a dedicated and/or companion alternator. Another reason for the increased cost is that the auxiliary equipment commonly used with prior art multiple traction motor systems is much larger than a fixed frequency and/or voltage component.
In addition, the use of software to control a locomotive is known in the art. For example, U.S. Pat. No. 7,124,691 to Donnelly et al. discloses a comprehensive logic and software system to monitor, control, and optimize the locomotive power including control over individual drive axles, especially during acceleration and braking. This system includes: a method of load control for the prime energy source; a method of releasing locked wheels; and a method of accurately controlling the speed of the locomotive in the low speed range. The disclosure is based on a locomotive that utilizes a DC power source. However, the system described in this reference suffers from many of the deficiencies of other prior art multiple traction motor systems discussed hereinabove.
Accordingly, a need exists for a stable source of electrical energy by utilizing utility proven components to synchronize, provide load sharing, and protection of the generation on the AC side. A further need exists for a system to rectify this stable, reliable, constant frequency AC voltage to provide a software defined load characteristic, thereby optimizing traction motor performance.